Pilot-operated type electromagnetic valve

Abstract

The invention relates to the technical field of electromagnetic valves, in particular to a pilot-operated type electromagnetic valve which comprises a main valve body, a liquid inlet and a liquid outlet are formed in the two ends of the main valve body respectively, a main valve cavity is formed in the main valve body, a valve seat is arranged in the main valve cavity, a valve plate is arranged in the main valve cavity, an upper valve cavity is formed above the valve plate, and a main valve spring is arranged in the upper valve cavity. A pilot cavity is formed in the main valve body, one or more scraping plates, a rotating assembly and a driving assembly are further arranged in the pilot cavity, the driving assembly is used for driving the rotating assembly to rotate, and the scraping plates are installed on the rotating assembly and used for rotationally scraping and cleaning the contact sealing face between the sealing piece and the pilot hole when the pilot hole is opened. The scraping plate is attached to the face, used for being in contact sealing with the pilot hole, of the bottom of the sealing part to conduct rotary scraping, the accumulation speed of the contact sealing face of the incrustation sealing part is effectively delayed, and the situation that liquid leaks from the pilot hole due to incrustation of the pilot-operated type electromagnetic valve is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of solenoid valves, in particular to a pilot-operated solenoid valve. Background Art

[0002] Pilot solenoid valve is a valve widely used in pipeline systems, usually used to control the passage and cutoff of pipelines. Pilot solenoid valve is generally used in pipeline systems with pressure difference, high pressure, large diameter, such as pipelines for tap water transportation.

[0003] In the pipeline system for tap water transportation, when the pilot solenoid valve is in use, the tap water will first enter the pilot chamber. When the electromagnet of the pilot valve is energized and started, the pilot hole is opened, and the tap water is discharged from the pilot chamber, thereby forming a pressure difference with low top and high bottom at the closure of the main valve, and the closure of the main valve is opened to achieve pipeline connectivity; when the electromagnet of the pilot valve is powered off, the spring force closes the pilot hole, and the inlet pressure quickly enters the chamber where the closure of the main valve is located through the bypass hole, and forms a pressure difference with low bottom and high top around the closure. The fluid pressure pushes the closure downward to close the valve and achieve pipeline isolation.

[0004] However, tap water contains some impurities, which can easily form scale inside the valve cavity of the pilot valve, especially in areas or countries with poor water quality. After the scale accumulates, the movable iron core of the pilot valve is prone to movement problems. After scale forms on the sealing contact surface of the pilot valve, it is also easy to produce gaps at the sealing surface, which in turn leads to poor sealing effect and leakage.

[0005] In order to solve the impact of scale on the pilot solenoid valve, the Chinese invention patent with application number: CN202110386151.5 and name "A pilot solenoid valve with anti-scale function" proposes a solenoid valve. The solenoid valve opens a groove on the fixed iron core, reduces the area of ​​the movable contact surface through the groove, and increases the flow rate at the groove, thereby effectively preventing scale from accumulating between the fixed iron core and the movable iron core, ensuring that the movable iron core will not be stuck due to scale accumulation.

[0006] However, the above invention patent does not have a descaling arrangement for the sealing surface between the movable iron core and the pilot hole. If scale accumulates on the sealing surface, it may easily lead to leakage at the pilot hole. This problem has yet to be solved.

[0007] Therefore, a pilot-operated solenoid valve is proposed. Summary of the invention

[0008] The object of the present invention is to provide a pilot-operated solenoid valve to solve the problem in the background art that the sealing member at the pilot hole is prone to leakage due to scale accumulation.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A pilot solenoid valve comprises a main valve body, wherein a liquid inlet and a liquid outlet are respectively arranged at two ends of the main valve body, a main valve cavity is arranged inside the main valve body, the main valve cavity is connected with the liquid inlet and the liquid outlet, a valve seat is arranged inside the main valve cavity, a valve plate is arranged inside the main valve cavity, an upper valve cavity is arranged above the valve plate, a main valve spring is arranged inside the upper valve cavity, the main valve spring is used to press the valve plate onto the valve seat to separate the liquid inlet from the liquid outlet; a pilot cavity is arranged on the main valve body, a pilot hole is arranged at the bottom of the pilot cavity, the pilot hole connects the liquid outlet and the pilot cavity, a first through hole and a second through hole are arranged on the main valve body, the first through hole connects the liquid inlet and the upper valve cavity, and the second through hole connects the upper valve cavity and the pilot cavity ; The main valve body is also provided with an electromagnetic assembly, which includes a movable iron core vertically slidably installed inside the pilot cavity, a closure member for closing the pilot hole is provided at the lower end of the movable iron core, a fixed iron core is provided above the movable iron core, a pilot spring is provided between the fixed iron core and the movable iron core, a coil is provided around the fixed iron core, and the electromagnetic assembly also includes a control assembly for controlling the power on and off of the coil; The pilot cavity is also provided with a scraper, a rotating assembly and a driving assembly, the scraper is one or more, the driving assembly is used to drive the rotating assembly to rotate, and the scraper is installed on the rotating assembly to rotate and scrape and clean the contact sealing surface between the closure member and the pilot hole when the pilot hole is opened. The pilot cavity is also provided with a cleaning block for scraping the end face of the pilot hole.

[0011] By arranging a scraper, a rotating assembly and a driving assembly inside the pilot cavity, when the fixed iron core absorbs the movable iron core upward and opens the pilot hole, the scraper is rotated and scraped against the surface of the sealing member for contacting and sealing with the pilot hole, which effectively delays the accumulation speed of scale on the contact sealing surface of the sealing member, and reduces the occurrence of leakage at the pilot hole of the pilot solenoid valve due to scale. The setting of the cleaning block helps to further prevent scale from accumulating on the end face of the pilot hole and reduce the impact of scale on the sealing effect of the pilot hole.

[0012] Preferably, the rotating assembly includes an annular groove coaxially opened with the pilot hole at the bottom of the pilot cavity, a turntable is rotatably installed inside the annular groove, the turntable is coaxially sleeved with the pilot hole, the upper end face of the turntable is flush with the end face of the pilot hole, and one or more vertically fixed columns are provided at the top edge of the turntable, the scraper is hinged to the upper side of the column, the scraper can swing up and down along the vertical direction, and a torsion spring is provided at the hinge position of the scraper and the column, and the torsion spring is used to keep the scraper lifted upward, and when the pilot hole is opened, the top of the scraper is horizontally fitted with the bottom of the closure; an avoidance gap is provided between the column and the closure in the horizontal direction, and when the closure is pressed downward to close the pilot hole, the side wall of the closure squeezes the scraper and makes the scraper be received in the avoidance gap.

[0013] By setting an avoidance gap between the column and the closure, the scraper is hinged on the column, so that when the closure is pressed down to close the pilot hole, the scraper can be automatically squeezed into the avoidance gap by the closure to avoid it, ensuring that the scraper will not interfere with the sealing of the pilot hole, thereby ensuring the sealing effect of the pilot solenoid valve, and the torsion spring automatically makes the scraper close to the bottom of the closure when the pilot hole is opened, ensuring that the scraper can effectively clean the closure.

[0014] At the same time, driven by the torsion spring, the movement of the scraper responds synchronously with the movement of the closure member, and there is no need for additional control of the scraper, thus saving the cost of controlling the scraper.

[0015] Preferably, the driving assembly includes a plurality of driving blocks fixedly mounted on the top surface of the turntable, the plurality of driving blocks are circumferentially evenly distributed at the edge of the turntable, a flow gap is provided between every two adjacent driving blocks, and a guide surface is provided on each of the driving blocks; the connecting port between the second through hole and the pilot cavity is located on the side wall of the pilot cavity, and the connecting port between the second through hole and the pilot cavity is aligned with the driving block in the vertical direction.

[0016] By setting the driving block and aligning the second through hole with the driving block, when the pilot hole is opened and the fluid in the pilot chamber is discharged from the pilot hole to the liquid outlet, the fluid in the upper valve chamber continuously enters the pilot chamber through the second through hole. When the fluid enters the pilot chamber from the second through hole, the fluid impacts the guide surface on the driving block, thereby giving the driving block a component force along the tangent direction of the turntable, thereby driving the driving block and the turntable to start rotating around the axis direction of the turntable. In this way, there is no need to set up an additional power source, and the turntable can be driven to rotate by only using the power of the fluid in the pilot chamber discharged from the pilot hole, and the driving component has a simple structure, saving production costs and maintenance costs.

[0017] Furthermore, in order to ensure that the turntable can be stably driven by the fluid, the width of the drive block and the flow gap are both smaller than the diameter of the second through hole during setting. This prevents the width of the drive block from being too wide and blocking the entire second through hole, which in turn causes the fluid to be unable to enter the pilot cavity from the second through hole and drive the turntable to rotate. In addition, making the width of the flow gap smaller than the diameter of the second through hole also prevents the flow gap from being too large and causing the flow gap to align with the second through hole, causing the fluid to flow directly through the flow gap and be unable to flush the guide surface, which in turn causes the fluid to be unable to drive the turntable to rotate. This further improves the use stability of the drive assembly. This ensures the use stability of the entire pilot solenoid valve during use.

[0018] Preferably, the cleaning block is horizontally slidably installed on the upper end surface of the turntable, an inclined guide ramp is arranged on the top of the cleaning block, a push spring is arranged between the cleaning block and the driving block, one end of the push spring is fixed on the driving block, and the other end is fixed on the cleaning block, and the push spring is used to keep the cleaning block pushed toward the axial direction of the pilot hole.

[0019] The push spring and the cleaning block are stored in the avoidance gap when the pilot hole is closed by the closing part. At this time, the push spring is in a compressed state, and the cleaning block will not affect the sealing effect of the closing part on the pilot hole. When the pilot hole is opened, the closing part moves upward with the movable iron core, and the push spring drives the cleaning block horizontally toward the direction of the pilot hole under the action of elastic force. When the push spring is in a natural state, the front end of the cleaning block facing the axis of the pilot hole is flush with the inner wall of the pilot hole, and the bottom of the cleaning block contacts the end face of the pilot hole. During the rotation of the turntable, the cleaning block rotates around the axis of the turntable with the turntable, and the bottom of the cleaning block rotates and scrapes the end face of the pilot hole to reduce the accumulation of scale on the end face of the pilot hole and avoid the accumulation of scale on the end face of the pilot hole affecting the sealing effect of the pilot hole.

[0020] When the coil is powered off, the fixed iron core no longer absorbs the movable iron core. When the movable iron core moves downward under the push of the pilot spring, the closing piece at the lower end of the movable iron core moves downward with the movable iron core. Then the closing piece squeezes the guide slope and gives a horizontal component force to the cleaning block, automatically squeezing the cleaning block to the avoidance gap, and the closing piece re-closes the pilot hole.

[0021] Preferably, the cross section of the scraper is an isosceles triangle, the base of the isosceles triangle faces upward, and when the pilot hole is opened, the base of the scraper with the isosceles triangle cross section fits horizontally with the bottom of the sealing member. When the scraper follows the rotation of the turntable, the scraper and the water or other fluid in the pilot chamber produce relative motion. When the water or other fluid flows through the bottom of the scraper, since the bottom of the scraper is inclined, the fluid will give the scraper an upward component force, and the scraper can be squeezed upward by this upward component force, so that the top surface of the scraper is more closely fitted with the sealing member, which helps to further ensure the scale cleaning effect of the scraper on the sealing member.

[0022] Preferably, one of the driving blocks is fixedly mounted with a guide rod horizontally along the diameter direction of the turntable, and a guide hole cooperating with the guide rod is also provided on the cleaning block. The cleaning block is slidably connected to the guide rod through the guide hole, and the push spring is evenly arranged on the guide rod. The arrangement of the guide rod and the guide hole can fix the height of the cleaning block in the vertical direction, so that the bottom of the cleaning block can stably contact the end face of the pilot hole, ensuring that the cleaning block can effectively scrape and clean the end face of the pilot hole. In addition, the guide rod is rigid, which can prevent the cleaning block from swinging due to the resistance of the fluid inside the pilot chamber when following the rotation of the turntable, further ensuring the cleaning effect of the cleaning block on the end face of the pilot hole.

[0023] Preferably, a plurality of balls are installed on the inner ring and the outer ring of the turntable, and the plurality of balls are evenly distributed on the turntable along the axis of the turntable. The balls effectively reduce the friction between the inner ring, the outer ring and the side wall of the ring groove of the turntable, which helps to further increase the rotation speed of the turntable, thereby improving the cleaning effect of the scraper on the seal, and also improving the cleaning effect of the cleaning block on the end face of the pilot hole, thereby preventing scale from affecting the sealing effect at the pilot hole.

[0024] Preferably, the cleaning block is also provided with a plurality of circular through holes horizontally, and the circular through holes are used to reduce the resistance of the fluid encountered by the cleaning block when the cleaning block rotates with the turntable. The provision of the circular through holes increases the rotation speed of the turntable, improves the cleaning effect of the scraper and the cleaning block, and further prevents scale from affecting the sealing effect at the pilot hole.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. Compared with the existing pilot solenoid valve, a pilot solenoid valve designed by the present invention has a scraper, a rotating assembly and a driving assembly arranged inside the pilot chamber. When the fixed iron core absorbs the movable iron core upward and opens the pilot hole, the scraper is rotated and scraped against the surface of the bottom of the closure used for contact sealing with the pilot hole, which effectively delays the speed of accumulation of scale on the contact sealing surface of the closure and reduces the occurrence of liquid leakage at the pilot hole of the pilot solenoid valve due to scale.

[0027] 2. A pilot solenoid valve designed by the present invention sets an avoidance gap between the column and the closure member, allowing the scraper to be hinged on the column, so that when the closure member is pressed down to close the pilot hole, the scraper can be automatically squeezed into the avoidance gap by the closure member to avoid it, ensuring that the scraper will not interfere with the sealing of the pilot hole, thereby ensuring the sealing effect of the pilot solenoid valve, and the torsion spring automatically makes the scraper close to the bottom of the closure member when the pilot hole is opened, ensuring that the scraper can effectively clean the closure member.

[0028] 3. A pilot solenoid valve designed by the present invention is also slidably mounted with a cleaning block on the turntable. When the pilot hole is opened, the cleaning block extends horizontally from the avoidance gap toward the end face of the pilot hole under the action of a push spring. When the cleaning block rotates with the turntable, the end face of the pilot hole is scraped and cleaned, thereby reducing the accumulation rate of scale on the end face of the pilot hole, and further preventing the pilot solenoid valve from leaking at the pilot hole due to scale accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0030] Figure 2 It is a front view of the present invention;

[0031] Figure 3 It is a schematic diagram of the internal structure of the present invention;

[0032] Figure 4 For the present invention Figure 3 The enlarged view of point A in the middle;

[0033] Figure 5 It is a structural schematic diagram of the present invention when the sealing member seals the pilot hole after the coil is powered off;

[0034] Figure 6 For the present invention Figure 5 The enlarged view of point B in the middle;

[0035] Figure 7 For the present invention Figure 5 Enlarged view of point C in the middle;

[0036] Figure 8 It is a three-dimensional diagram of the assembly of the rotating disk, the scraper and the cleaning block of the present invention.

[0037] In the figure: 1. main valve body; 2. liquid inlet; 3. liquid outlet; 4. main valve chamber; 5. valve seat; 6. valve plate; 7. upper valve chamber; 8. main valve spring; 9. pilot chamber; 10. pilot hole; 11. first through hole; 12. second through hole; 13. movable iron core; 14. closure; 15. fixed iron core; 16. pilot spring; 17. coil; 18. control assembly; 19. scraper; 20. annular groove; 21. turntable; 22. column; 23. torsion spring; 24. avoidance gap; 25. drive block; 26. flow gap; 27. guide surface; 28. cleaning block; 29. ​​guide ramp; 30. push spring; 31. guide rod; 32. guide hole; 33. ball; 34. circular through hole. DETAILED DESCRIPTION

[0038] See also Figures 1 to 8 The present invention provides a pilot solenoid valve, and the technical solution is as follows:

[0039] A pilot solenoid valve, reference Figure 3 , comprising a main valve body 1, wherein a liquid inlet 2 and a liquid outlet 3 are respectively arranged at both ends of the main valve body 1, a main valve cavity 4 is arranged inside the main valve body 1, the main valve cavity 4 is connected with the liquid inlet 2 and the liquid outlet 3, a valve seat 5 is arranged inside the main valve cavity 4, a valve plate 6 is arranged inside the main valve cavity 4, an upper valve cavity 7 is arranged above the valve plate 6, and a main valve spring 8 is arranged inside the upper valve cavity 7; a pilot cavity 9 is arranged on the main valve body 1, a pilot hole 10 is arranged at the bottom of the pilot cavity 9, the pilot hole 10 is connected with the liquid outlet 3 and the pilot cavity 9, a first through hole 11 and a second through hole 12 are arranged on the main valve body 1, and the first through hole 11 connects the liquid inlet 2 with the upper valve chamber 7, and the second through hole 12 connects the upper valve chamber 7 with the pilot chamber 9; an electromagnetic assembly is also provided on the main valve body 1, and the electromagnetic assembly includes a movable iron core 13 vertically slidably installed inside the pilot chamber 9, and a closing piece 14 for closing the pilot hole 10 is provided at the lower end of the movable iron core 13, and a fixed iron core 15 is provided above the movable iron core 13, and a pilot spring 16 is provided between the fixed iron core 15 and the movable iron core 13, and a coil 17 is provided around the fixed iron core 15, and the electromagnetic assembly also includes a control assembly 18 for controlling the power on and off of the coil 17.

[0040] refer to Figures 3 to 8A rotating assembly is also provided inside the pilot cavity 9, and the rotating assembly includes an annular groove 20 coaxially opened at the bottom of the pilot cavity 9 and the pilot hole 10, and a turntable 21 is rotatably installed inside the annular groove 20, and the turntable 21 is coaxially sleeved with the pilot hole 10, and the upper end surface of the turntable 21 is flush with the end surface of the pilot hole 10, and a column 22 is provided at the top edge of the turntable 21, and a scraper 19 is rotatably installed on the upper side of the column 22, and the scraper 19 is hinged to the upper side of the column 22, and the scraper 19 can swing up and down along the vertical direction, and a torsion spring 23 is provided at the hinge position of the scraper 19 and the column 22, and the torsion spring 23 is used to keep the scraper 19 lifted upward, and the cross-section of the scraper 19 is an isosceles triangle, and the base of the isosceles triangle faces upward; an avoidance gap 24 is provided between the column 22 and the closing member 14 in the horizontal direction.

[0041] refer to Figure 8 Four balls 33 are evenly distributed on the inner ring and the outer ring of the turntable 21 with the axis of the turntable 21 as the reference circumference.

[0042] refer to Figures 3 to 6 as well as Figure 8 , a driving assembly for driving the turntable 21 to rotate is also provided inside the pilot cavity 9, and the driving assembly includes a plurality of driving blocks 25 fixedly mounted on the top surface of the turntable 21. Among them, the column 22 of the rotating assembly is fixedly mounted on the top of one of the driving blocks 25. The plurality of driving blocks 25 are evenly distributed around the edge of the turntable 21, and a flow gap 26 is provided between every two adjacent driving blocks 25, and a guide surface 27 is provided on each driving block 25; the connecting port between the second through hole 12 and the pilot cavity 9 is located on the side wall of the pilot cavity 9, and the connecting port between the second through hole 12 and the pilot cavity 9 is aligned with the driving block 25 in the vertical direction, and the width of the driving block 25 and the flow gap 26 are both smaller than the diameter of the second through hole 12.

[0043] refer to Figure 3 , Figure 7 and Figure 8, one of the driving blocks 25 is fixedly installed with a guide rod 31 horizontally along the diameter direction of the rotating disk 21, and the rotating disk 21 is also provided with a cleaning block 28 for scraping the end surface of the pilot hole 10, and a guide hole 32 matching the guide rod 31 is horizontally opened on the cleaning block 28, and the cleaning block 28 is horizontally slidably connected with the guide rod 31 through the guide hole 32, and the bottom of the cleaning block 28 is horizontally slidably contacted with the rotating disk 21, and an inclined guide slope 29 is arranged on the top of the cleaning block 28, and the guide slope 29 is located on the side close to the pilot hole 10, and the guide slope 29 is inclined downward in the direction of the rotating disk 21, and a push spring 30 is arranged between the cleaning block 28 and the driving block 25, and the push spring 30 is evenly arranged on the guide rod 31, one end of the push spring 30 is fixed on the driving block 25, and the other end is fixed on the cleaning block 28, and the push spring 30 is used to keep the cleaning block 28 pushed toward the axial direction of the pilot hole 10. A plurality of circular through holes 34 are also horizontally opened on the cleaning block 28.

[0044] When using, refer to Figure 3 , Figure 5 , Figure 6 , Figure 7 as well as Figure 8 When the electromagnetic coil 17 is powered off, the movable iron core 13 moves downward under the elastic force of the pilot spring 16, and the closure member 14 at the bottom of the movable iron core 13 is pressed and contacted with the end face of the pilot hole 10, and the pilot hole 10 is closed. At the same time, when the closure member 14 moves downward, it will squeeze the scraper 19 below the closure member 14. The scraper 19 rotates downward under the pressure of the closure member 14 and is squeezed into the escape gap 24 by the closure member 14. Finally, the scraper 19 is received in the escape gap 24, and the torsion spring 23 is compressed. As the closure member 14 continues to move downward, the bottom of the closure member 14 will be pressed and contacted with the guide slope 29 on the cleaning block 28. The closure member 14 will give the guide slope 29 a horizontal pressure, and the horizontal pressure will eventually squeeze the cleaning block 28 into the escape gap 24, and the push spring 30 will be compressed at this time. Subsequently, the fluid on the side of the liquid inlet 2 flows into the upper valve chamber 7 from the first through hole 11. Under the fluid pressure of the upper valve chamber 7 and the elastic force of the main valve spring 8, the valve plate 6 is squeezed toward the valve seat 5. The valve plate 6 is pressed on the valve seat 5 to separate the liquid inlet 2 from the liquid outlet 3, and the entire valve is closed. At this time, the fluid will also flow from the upper valve chamber 7 through the second through hole 12 and fill the pilot chamber 9.

[0045] refer to Figure 3 , Figure 4 , Figure 6 and Figure 8When the electromagnetic coil 17 is energized, the fixed iron core 15 is magnetized, the movable iron core 13 is attracted upward under the action of the magnetic force of the fixed iron core 15, the pilot spring 16 is compressed, and the closure 14 also moves upward with the movable iron core 13. At this time, under the elastic force of the torsion spring 23, the scraper 19 also starts to rotate upward following the movement of the closure 14, and finally the top of the scraper 19 fits with the bottom of the closure 14. At the same time, the extrusion limit of the closure 14 is lost, and the cleaning block 28 also moves horizontally toward the axial direction of the pilot hole 10 under the elastic force of the push spring 30, and finally the end of the cleaning block 28 is flush with the inner wall of the pilot hole 10, and the bottom of the cleaning block 28 is in sliding contact with the end face of the pilot hole 10. After the closure 14 moves upward, the pilot hole 10 is opened. The fluid inside the pilot cavity 9 is discharged from the pilot hole 10 outside the pilot cavity 9 and enters the outlet 3 from one side of the main valve cavity 4. As the fluid in the pilot chamber 9 is discharged, the fluid in the upper valve chamber 7 also continuously flows into the pilot chamber 9 from the second through hole 12. When the fluid enters the pilot chamber 9 from the second through hole 12, the fluid impacts the guide surface 27 on the driving block 25, thereby giving the driving block 25 a component force along the tangential direction of the rotating disk 21. The component force in the tangential direction drives the rotating disk 21 to start rotating around the axis direction of the pilot hole 10. During the rotation of the rotating disk 21, the scraper 19 rotates with the rotating disk 21 and the top of the scraper 19 is in contact with the bottom of the closure 14 for scraping, thereby reducing the accumulation of scale at the bottom of the closure 14. At the same time, the cleaning block 28 also rotates with the rotating disk 21, and the bottom of the cleaning block 28 scrapes and cleans the end face of the pilot hole 10, thereby reducing the accumulation of scale at the end face of the pilot hole 10.

[0046] When the fluid in the pilot chamber 9 and the upper valve chamber 7 is discharged from the pilot hole 10 to the liquid outlet 3 from the main valve chamber 4 on one side, the pressure in the upper valve chamber 7 decreases rapidly, and a pressure difference of high at the bottom and low at the top is formed at the valve plate 6. The pressure of the fluid lifts the valve plate 6 from the bottom to the top, the valve plate 6 is separated from the valve seat 5, the liquid inlet 2 is connected to the liquid outlet 3, and the valve opens.

[0047] When the coil 17 is powered off, the valve repeats the above operation to isolate the liquid inlet 2 from the liquid outlet 3, and the valve is closed.

[0048] In addition, in order to improve the cleaning effect of the scraper 19 on the scale at the bottom of the closure 14, multiple scrapers 19 and columns 22 can be provided. Correspondingly, multiple cleaning blocks 28 can also be provided without interference.

[0049] A specific embodiment of the present invention is described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above described embodiment. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments without departing from the principles and ideas of the present invention should still fall within the scope of protection of the present invention.

Claims

1. A pilot-operated solenoid valve, comprising a main valve body (1), wherein two ends of the main valve body (1) are respectively provided with a liquid inlet (2) and a liquid outlet (3), wherein a main valve chamber (4) is provided inside the main valve body (1), wherein a valve seat (5) is provided inside the main valve chamber (4), wherein a valve plate (6) is provided inside the main valve chamber (4), wherein an upper valve chamber (7) is provided above the valve plate (6), wherein a main valve spring (8) is provided inside the upper valve chamber (7); wherein a pilot chamber (9) is provided on the main valve body (1), wherein a A pilot hole (10), a first through hole (11) and a second through hole (12) are provided on the main valve body (1); an electromagnetic assembly is also provided on the main valve body (1), the electromagnetic assembly comprises a movable iron core (13) inside the pilot cavity (9), a closing member (14) is provided at the lower end of the movable iron core (13), a fixed iron core (15) is provided above the movable iron core (13), a pilot spring (16) is provided inside the pilot cavity (9), and a coil (17) is provided around the fixed iron core (15); characterized in that, A scraper (19), a rotating assembly and a driving assembly are also provided inside the pilot cavity (9). The driving assembly is used to drive the rotating assembly to rotate. The scraper (19) is installed on the rotating assembly. When the pilot hole (10) is opened, the scraper (19) rotates with the rotating assembly and scrapes and cleans the contact sealing surface of the closure (14). A cleaning block (28) for scraping the end surface of the pilot hole (10) is also provided inside the pilot cavity (9).

2. A pilot-operated solenoid valve according to claim 1, characterized in that: The rotating assembly comprises an annular groove (20) coaxially arranged at the bottom of the pilot cavity (9) and the pilot hole (10); a rotating disk (21) is rotatably mounted inside the annular groove (20); the rotating disk (21) is coaxially sleeved with the pilot hole (10); the upper end surface of the rotating disk (21) is flush with the upper end surface of the pilot hole (10); one or more columns (22) corresponding to the scraper (19) are arranged at the top edge of the rotating disk (21); the scraper (19) is hinged to the upper side of the column (22); the scraper (19) can swing up and down along the vertical direction; the scraper A torsion spring (23) is provided at a hinged position between the scraper (19) and the column (22), and the torsion spring (23) is used to keep the scraper (19) lifted upward. When the pilot hole (10) is opened, the top of the scraper (19) is horizontally fitted with the bottom of the closing member (14); an avoidance gap (24) is provided between the column (22) and the closing member (14) in the horizontal direction. When the closing member (14) is pressed downward to close the pilot hole (10), the side wall of the closing member (14) squeezes the scraper (19) and allows the scraper (19) to be stored in the avoidance gap (24).

3. A pilot-operated solenoid valve according to claim 2, characterized in that: The driving assembly comprises a plurality of driving blocks (25) fixedly mounted on the top surface of the rotating disk (21); the plurality of driving blocks (25) are evenly distributed around the edge of the rotating disk (21); a flow gap (26) is provided between every two adjacent driving blocks (25); and a flow guide surface (27) is provided on each of the driving blocks (25); the communication opening between the second through hole (12) and the pilot cavity (9) is located on the side wall of the pilot cavity (9); the communication opening between the second through hole (12) and the pilot cavity (9) is aligned with the driving block (25) in the vertical direction; and the width of the driving block (25) and the flow gap (26) are both smaller than the diameter of the second through hole (12).

4. A pilot-operated solenoid valve according to claim 3, characterized in that: The cleaning block (28) is horizontally slidably mounted on the upper end surface of the rotating disk (21); an inclined guide slope (29) is arranged on the top of the cleaning block (28); a push spring (30) is arranged between the cleaning block (28) and the driving block (25); one end of the push spring (30) is fixed on the driving block (25) and the other end is fixed on the cleaning block (28); the push spring (30) is used to keep the cleaning block (28) pushed toward the axial direction of the pilot hole (10); when the push spring (30) is in a natural state, the front end of the cleaning block (28) facing the axial direction of the pilot hole (10) is flush with the inner wall of the pilot hole (10); when the movable iron core (13) moves downward, the closing member (14) presses the guide slope (29) and presses the cleaning block (28) to the avoidance gap (24).

5. A pilot-operated solenoid valve according to claim 2, characterized in that: The cross section of the scraper (19) is an isosceles triangle, with the base of the isosceles triangle facing upwards. When the pilot hole (10) is opened, the base of the scraper (19) with the isosceles triangle cross section is horizontally fitted with the bottom of the closure member (14).

6. A pilot-operated solenoid valve according to claim 4, characterized in that: One of the driving blocks (25) is fixedly mounted with a guide rod (31) horizontally along the diameter direction of the turntable (21); a guide hole (32) cooperating with the guide rod (31) is also formed on the cleaning block (28); the cleaning block (28) is slidably connected to the guide rod (31) through the guide hole (32); and the push spring (30) is wound around the guide rod (31).

7. A pilot-operated solenoid valve according to claim 2, characterized in that: A plurality of balls (33) are mounted on the inner ring and the outer ring of the rotating disk (21), and the plurality of balls (33) are evenly distributed on the rotating disk (21) along the axis of the rotating disk (21).

8. The pilot-operated solenoid valve according to claim 4, characterized in that: The cleaning block (28) is also horizontally provided with a plurality of circular through holes (34).

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